Coffer



2 Sheets-Sheet 1.

(No Model.)

a; CLARKE. COPPER DAM FOR VESSELS NOQ 395,265.

Patent-edDec. 25, 1888.

FIG. 2.

T e e h A S t e e h S 2 G. CLARKE. COPPER DAM FOR VESSELS.

Pafsented Dec. 25, 1888-.

(NdModeL) NO. 395,Z 65.

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WIlZmsse-s lUivi'rEn Srnrns Pnrnnr Cerise,

GEORGE CLARKE, OF JERSEY CITY, NEIV JERSEY, ASSIGNOR TO HORACE G. PHILIPS, OF IVILMINGTON, DELAIVARE.

COFFEE-DAM FOR VESSELS.

SPECIFICATION forming part of Letters Patent No. 395,265, dated December 25, 1888. Application filed October 3, 1888. Serial No. 287,104 (No model.)

To all whom it may concern:

. Be it known that I, GEORGE CLARKE, a citizen of the United States, and a resident of Jersey City, New Jersey, have invented certain Improvements in Coffer-Dams for Vessels, of which the following is a specification.

One object of my invention is to fit the gates of a coffer-dani to the shape of a vessel, so that they will be practically water-tight without the extended use of oakum or other packing, a further object of my invention being to so construct the coffer-dam that it will be narrow, and at the same time allow for the removal or rotation of the twin screw-propellers, as fully described hereinafter, reference being had to the accompanying drawings, in which- Figure 1 is a perspective view of sufficient of my improved coffer-dam to illustrate the invention. Fig. 2 is an end view. Fig. 3 is a transverse section on the line 1 2, Fig. 1. Fig. 4 is a sectional plan on the line 3 4, Fig. 3, of a portion only of the coifer-dam and Fig. 5 is a sectional plan view of one of the gates.

My invention relates especially to colferdams built for use under steamships of the twin-screw typethat is, steamships having propellers on each side.

The great difficulty has heretofore been to thoroughly pack the joints between the gates of the coffer-dani and the sides of the vessel, owing to the irregular shape caused by the extension of the plating for the propellershafts. I overcome this objection in the following manner:

Referring to the drawings, A is the main body of the coffer-dam, composed of the base or bottom A and the sides B B, the permanent end C, and the gates D D, hinged at d to the sides 13 B in any suitable manner. These gates are of a form corresponding to the general contour of the vessels hull, excepting at the points where the plating of the screw-shaft ways project.

Extending around the edge of each gate D is a flexible pipe or hose, E, having an inlet, 6, and at the opposite end aplug, c. This hose is embedded in a groove in the edge, and when the gate is closed and hydraulic steam or air pressure is applied to the hose it is expanded against the hull of the vessel, as well as against the base A and sides B, thus dispensing with the usual packing to make a tight joint between the vessel and the gates, sides, and bottom of the coffer-dam.

By referring to Fig. 2 of the drawings it will be seen that I provide small sliding gates F G of peculiar shape to fit the contour of the hull of the vessel at the points where the propellershaft bearings or ways project from the sides of the vessel. It will be noticed that two deep recess, 2' t", are thus formed in each side of the shaft bearings or ways.

The main gates D I) cannot be made to fit the recesses i i, but must have an independent gate, which passes into the recesses from the main. gate after the main gate is in position against the side of the vessel.

If the coffer-dam is applied to the vessel from the under side, the recesses 2' could be fitted by a permanent extension on the main gate; or, if the cotter-dam is applied to the vessel before the gates are closed, the recesses could be fitted with a permanent extension; but I prefer to have a supplementary sliding gate, G, to fit both recesses, so that when it'is necessary to place the coffer-dam under a vessel of the central-screw type these gates will answer by merely filling up the opening d in the gates made for the extension of the shaftbearings. This may be done by a separate piece of material, or may be closed by a gate, (shown by dotted lines in Fig. 1,) when found necessary. 7

The gates F and G may be operated through any of the well-known devices. I have shown in the drawings the gates F sliding in ways f and having pins which pass through. elongated slots in levers f, pivoted at f to the main gate. The other arms of these levers are attached to vertical rods f having suitable handles at their upper end. By moving the rods vertically the gates will be opened or closed and secured either in the raised or depressed position by anysuitable catches. The

gates G slide in ways g g and are connected to handled levers g by links g The handled levers are pivoted to the main gates D at g. By moving these levers transversely the gates G will be moved into or out of the recesses t" and locked in either of the positions by any suitable fastening. The gates D D can swing out at right angles, as shown in the perspective view, so as to clear the stern of the vessel. They are held in this open position by bolts I I on the sides B B. These bolts pass through eyes h on the gates D D.

When the coffer-dam is moved away from the vessel, the gates are closed and a supple mentary gate, D, hinged to the base of the coffer-dam, is moved into position, so as to close up the keel-opening formed in the gates D D.

On each side and at the back of the cofferdam are a series of water-ballast spaces at the points indicated, to form pockets or recesses M M upon the inside of the coifer-dam immediately opposite each propeller wh en the coffer-dam is in position under the vessel. The object of providing these recesses is to allow the propellers to be turned in the case of repairing or to allow for the withdrawal of the propeller from the shaft. By making these recesses in the sides of the coffer-dam I am enabled to make a much narrower cofferdam than heretofore, which is an essential feature of construction, as it will be noticed on referring to Fig. 3 that if the propellerblades are brought to the position shown in that figure the coifer-dam can be placed in position, and when recesses are opposite the propeller-blades the propellers can be revolved without interfering with the colfer-dam.

In some instances I use, together with the hose, strips of canvas, .9, or other suitable material secured along the inner edges of the ship, the pressure of water on the outside forcing the canvas 3 against the hull of the vessel and making a tight joint.

It will be understood that the hose and canvas can be applied to the edges of the gates used in coffer-dams of the ordinary construction without departing from my invention.

I claim as my invention- 1. The combination, in a coffer-dam for twin-screw vessels, of the swinging main gates and supplemental gates carried thereby and adapted to the irregularities of the hull of the vessel, substantially as described.

2. The combination, in a coffer-dam for a vessel, of the pivoted gates therefor, grooved on their edges, with a hose adapted to the grooves, and with means for expanding said hose when the gates are closed, substantially as and for the purpose described.

3. The combination, in a coffer-dam for twin-screw vessels, of the side walls, B B, having recesses M M opposite the propellers of the vessel, substantially as and for the purpose set forth.

4. The combination, in a coffer-dam for vessels, of the side frames, the gates hinged thereto and adapted to swing into a position in line with said side frames, and a bolt adapted to secure the gates in this open position, substantially as described.

5. The combination, in a co'ifer-dam, of the gates having grooved edges, with a hose adapted to said grooves, and a strip of flexible material secured to the inner edges of said gates and extending between the hose and the hull of the vessel and beyond the hose, substantially as described.

In testimony whereof I have signed my name to this specification in the presence of two subscribing witnesses.

GEORGE CLARKE.

Witnesses:

WILLIAM D. OoNNnR, HARRY SMITH. 

